Air venting valve for heating system



Jan. 8, 1957 w, FERGUSON 2,776,671

AIR VENTING VALVE FOR HEATING SYSTEM Filed Oct. 8, 1953 as 3e 8 3 4a 48 6e a e0 26 /4 8 6&3 64/68/17 16 5 Warr'w 171 522 980802? 5y M64 United States Patent AIR VENTING VALVE FOR HEATING SYSTEM Warren T. Ferguson, Newton Highlands, Mass, assignor to Anderson Products, Incorporated, Cambridge, Mass, a corporation of Massachusetts Application October 8,1953, Serial N 0. 384,865 I 6 Claims. (Cl. 137197) This invention relates to air venting valves. It is particularly concerned with an air vent which may be used in connection with a hot water heating system to vent quickly the air in each individual radiator at the beginning of the heating season and which will function thereafter to vent slowly such air as may accumulate in each radiator as the heating season progresses.

The conventional practice up to the present in hot water heating systems of the type commonly used in homes is to provide a small key operated valve located near the top of each radiator. At the beginning of each heating season the system is filled with water. The trapped air at thetop of each radiator is permitted to escape by opening the key operated valve and after the radiator isfilled with water and the air expelled, the valve is closed. Thereafter, as the heating cycles are repeated again and again air that is present in the water gradually escapes therefrom to accumulate in the top of each radiator. Thus, the water level in each radiator gradually falls and the heating efiiciency correspondingly declines.

When the water level in the radiator falls as the air separates out, it becomes necessary to restore the water level if full efficiency is'to be maintained. The water level may be restored by opening the valve from the water main or utilizing Water stored in a separate tank connected with the system which is under suflicient pressure to force the water up to the radiators. In the previous practice when the water level is being restored, manual opening of each radiator valve has been required. Since this is attended to at irregular intervals, heating efficiency will not be as good as it could be.

Therefore, it is an object of the present invention to provide a valve of such character and construction that it may be substituted for the present k'ey actuated valve to permit the immediate and continuous escape from the radiator of any air that collects in the upper portion. This assumes of course that there is a suitable supply of water under adequate pressure to raise the level in the radiator and to expel the gas therefrom.

The valve in addition to its automatic air venting qualities is designed to permit quick venting by manual actuation at any time. Ordinarily, this quick venting operation will occur only at the beginning of each season. Thereafter, venting will be automatic as the water level r1ses.

Another object of the invention is to provide an air venting valve of such construction that substantially no water will be present in the valve when venting commences as the water level in the radiator rises. In previous constructions, it has been found that capillary attraction or other phenomena has caused water or condensate to collect and remain in the threaded opening of the radiator and in the entrance port of the air venting valves .used therewith as the water level falls and air collects in the upper part of the radiator. Thereafter, as the water level rises or the air pressure otherwise increases to drive out the collected air, the water held by capillary attraction in the threaded opening and entrance passage to the valve is driven ahead of the air and into the hygroscopic disks. The amount of water so present in the prior art structures has been of such volume as to greatly delay the desired escape of the compressed air in the radiator. Such escape of air is delayed until the expanded disks can thereafter contract through the evaporation of this relatively large volume of water therein after which the air may be discharged.

Accordingly, the present construction includes mechanism which will eliminate or so greatly reduce the water in the valve passages that when driven by the internal air pressure into the hygroscopic disks, it will be of such small amount that the disks will quickly evaporate it to a degree sufficient to permit the escape of air. Thus, venting can proceed immediately in the normal manner and the disks will not be sealed again until the arrival of water in the valve from the raised water level.

A further object of the invention is the provision of a construction which will permit quick and easy cleaning of the venting passage through the valve. Occasionally, scum or other foreign matter in the water of the radiator will cause clogging of the valve to such degree that it will not work properly. In such case, it is desirable that the valve may be cleared of the obstruction without having to remove it from the radiator. The present invention provides a metering screw which may be removed from the valve without removing the valve from the radiator and upon removal of such screw, a cleaning element such as a wire may be inserted into the valve to clean it to restore it to proper operating condition.

These and other objects of the invention will become more apparent as the description proceeds with the aid of the accompanying drawings in which Fig. l is a vertical cross-section of the valve shown in position in the wall of the radiator.

Fig. 2 is an enlarged fragmentary section of the plug, metering screw, and hygroscopic disks to show the character of the engaging threads.

Fig. 3 is a vertical section on the line 3-3 of Fig. 1.

Referring to Fig. 1, the valve comprises a body 2 having a pipe thread 4 on its exterior and a central passage 6. The body expands into a hexagonal nut portion 8 having a terminal flange 10 with a threaded interior bore A cap 14 threaded exteriorly at its lower end at 16 is adapted to make screw threaded engagement with the threads 12. The terminal flange 10 is shown as being crimped over at 20 to prevent the removal of the cap after it has been threaded into position.

A plug 22 having a shoulder 24 fits tightly within the interior end of the cap 14 as at 18. Plug 22 engages a corresponding shoulder 26 in the cap and is held in this position by the flared over end 28 on the interior end of the cap. In this manner, a cavity 29 of fixed dimensions is provided in the member comprised of cap 14 and plug 22.

Plug 22 has a central bore 30 threaded overthe majority of its length as at 32 which threads are designed to receive the corresponding threads of a metering screw 34 whose head 36 is positioned in a centrally located recess38 in the outer surface of cap 14. A washer 40 provides for leakproof engagement of head 36 with the bottom of recess 38.

In the cavity 29, between the right hand end of plug 22 and the under side of the closed end of cap 14 are a plurality of hygroscopic elements in the form of annular fiber disks 42. In the present instance, six disks are shown. These disks may be of any selected configuration, such as circular or multisided or with notches therein. In the preferred form shown herein, the disks are circular and of such diameter as to give adequate clearance with the interior cylindrical surface 44 of the cap. The holes in the center of the disks likewise make clearance with the screw 34.

Extending around the circumference of cap 14 are a plurality of venting ports 46 shown in Figs. 1 and 3. These ports are designed to permit escape of air from the cavity 29 that has passed through the disks and to permit subsequent evaporation of water that may have reached and expanded the disks.

Plug 22 at its left end has a short extension 48. which has positioned thereon a circular sealing ring 50 which in Fig. l is shown in compressed condition and acts to seal the area 52 about the exterior of the sealing ring from the passage 6. A fast venting port 54 through the wall 10 of the body 2 is provided which becomes effective for quick venting of air or water when the cap 14 is screwed outwardly freeing the sealing ring from its engagement with the surface 56 at the base of the threaded portion 10.

Since the plug 22 is in fixed engagement with shoulder 26 of the cap, tightening up of screw 36 will cause no movement of the plug in relation to the cap 14. In other words, the space or cavity in which are positioned the six hygroscopic disks will not be varied by actuation of screw 36. Thus, with the disks made the right size for the space to be filled, there can be no maladjustment through actuation or removal of the metering screw 34.

Attention is called to Fig. 2 in which the metering screw 34 is shown to have a rolled thread 58, whereas the thread 60 on the plug 22 is a cut thread made A of an inch oversize. Thus, when screw 34 is set up tight, there will be a continuous small helical passage 62 running from the passage 30, the length of the engaging threads 58 and 60 to the area within the disks 42. The passage 62 is such size that air or water or a mixture of both can flow slowly therethrough, but at a rate adequate to cause the valve to function as intended. Thus, the screw 34 acts to meter the rate of discharge of the fluids, but it has no effect on the position of plug 22 with respect to the cap.

Positioned within bore 6 of the threaded end of the valve body is a tube 64 secured in any convenient manner. It will be noticed that tube 64 is long enough to extend beyond the end 66 of the valve, and, in accord with the extent of the entry of thread 4 into the radiator wall, may also extend beyond the inner wall 68 of the radiator. Furthermore, it will be noted that the passage 70 through tube 64 is very much smaller than the bore 6, but still is large enough to permit free fiow of air or water Whose flow is more specifically controlled by the metering screw 34.

Tube 64 is shown as inserted in bore 6 far enough to come into engagement with the left hand end of plug 22 when the plug extension 48 is in such position that the sealing ring 50 is under maximum compression. This provides a continuous passage consisting of passage 70 through the tube and passage 30 in plug 22 leading to the helical passage 62 between the threads.

Condensate running down the inner wall of the radiator or the remains of the falling water level will collect in the threaded opening 72 where it may remain without interference with air being discharged through passage 70. The tube 64 by extending into the radiator makes it unnecessary for the disks 42'. to evaporate any water that may be in threaded opening 72, thereby greatly reducing the period of evaporation that must occur before air can be discharged through the hygroscopic disks 42.

Should the passage 70 inadvertently become clogged by foreign matter present in the radiator water, screw 34 may be removed to provide a straight opening consisting of the aligned passages 70 and 30 running from the interior of the radiator to the end of the valve. A wire or other instrument may then beinserted in these passages to remove the obstruction after which screw 34 may be replaced to resume its metering function.

The operation of the valve is as follows: If we assume that the water level in the radiator is at a level below the valve and additional water is added to the system, causing the water level to commence to rise with an increase in air pressure, air in the upper part of the radiator will be forced through the passages and 3t) and thence through the metering passage 62 and between the disks 42 and thence out to the atmosphere through the port 46. In due time the water level will rise to flow into passages 70 and 30 through metering passage 62 and thence into the hygroscopic disks 42. These disks will then promptly swell, increasing their thicknesses to such an extent that they will be tightly compressed between the right hand end of plug 22 and the under side of cap 14. This pressure will be so great that any further escape of water is effectively blocked.

Thereafter, when the water recedes to a level below passage 70, the water in the disks 42 will gradually evaporate together with the water remaining in passages 70, 30 and 62, which water will be moved either by capillary attraction or by radiator air pressure that is above atmospheric to the disks 42 to be evaporated. Upon evaporation of the water the disks will resume their normal spaced apart position which is shown in Fig. l. The valve will thus automatically return to a condition in which the passages 70, 30 and 62 are sufficiently free of water so that the valve is ready to vent air again whenever the air pressure in the radiator is above atmospheric.

In actual practice, the diameter of the passage 70 is about of an inch which will. indicate clearly the limited amount of water that could be retained therein as compared with the amount of water that would normally be present in passage 6- were the tube 64 not used.

Accordingly, there has been provided by the valve disclosed herein means for achieving continuous automatic venting of air from the radiators of a hot water heating system whenever the pressure in the radiator is above atmospheric and acting also to prevent the escape of water if the water rises to the level of the valve. While the explanation has been made with respect to the use of the valve on radiators of a hot water heating system, it will be understood that the valves are capable of being used in other situations where similar conditions have to be met. The invention is not to be limited by the specific disclosures herein shown but should be considered as broadly as the scope ofthe invention set forth in the appended claims.

I claim:

I. An air venting valve comprising a valve body threaded for connection with a radiator, a passage through said body, an extended portion forming part of said body, a cap closed at its outer end in threaded engagement with said extended portion, a plug within said cap, a circular seat on said body and an opposed circular surface on said plug aligned with said passage, a sealing ring positioned between said seat and surface and adapted to be engaged upon movement of said cap and plug towards said body to seal said passage from the area exterior of said ring, a threaded bore through said plug in series with said passage, a first vent through said body leading to the atmosphere from the area exterior of said sealing ring, a second vent through the wall of said cap and a hygroscopic element positioned in the space between one. end of said plug and the end of said cap, said hygroscopic element when dry permitting the passage of air from said plug bore to said second vent and when wet blocking the flow of water from said plug bore to said second vent, an opening through the end of said cap, a screw extending through said cap and hygroscopic element into engagement with said threaded plug bore to provide a metering passage between the threads of said plug bore and said screw, whereby upon the removal of said screw a cleaning tool may be inserted through said hygroscopic element, plug and passage and means for preventing leakage of fluid between said screw and cap when said screw is in metering position.

2. An air venting valve as set forth in claim 1 in which said passage is formed by a separate tube inserted into a larger bore within the threaded portion of said valve body, said tube being of such length as to extend beyond the inner wall of said radiator when said valve is positioned in operative condition in said radiator wall.

3. An air venting valve as set forth in claim 1 in which said plug is fixed with respect to said cap and the space between the said one end of said plug and the said inner surface of said cap is constant and not subject to adjustment.

4. An air venting valve as set forth in claim 1 in which said passage is formed by a separate tube inserted into a larger bore within the threaded portion of said valve body, said tube being of such length as to extend beyond the inner wall of said radiator when said valve is positioned in operative condition in said radiator wall, said plug is fixed with respect to said cap and the space between the said one end of said plug and the said inner surface of said cap is constant and not subject to adjustment.

5. An air venting valve as set forth in claim 1 in which said passage is formed by a separate tube inserted into a larger bore within the threaded portion of said valve body, said tube being of such length as to extend beyond the end of said valve body far enough to prevent condensate from the interior radiator wall collecting in said tube when said valve is in normal position in a radiator.

6. An air venting valve as set forth in claim 1, in which said passage is defined in part by a portion extending from the radiator end of said threaded valve body, said extended portion being of such length as to prevent condensate from the interior radiator wall collecting in said passage when said valve is in normal position in a radiator.

References Cited in the file of this patent UNITED STATES PATENTS 1,464,110 Ramsey Aug. 7, 1923 1,552,838 Gage Sept. 8, 1925 2,153,726 Scoppola Apr. 11, 1939 2,655,170 Ferguson Oct. 13, 1953 2,722,942 Hencken Nov. 8, 1955 

